function linkesterno() { 
if (!document.getElementsByTagName) return;
var anchors = document.getElementsByTagName("a"); 
for (var i=0; i<anchors.length; i++) { 
	var anchor = anchors[i]; 
	if (anchor.getAttribute("href") && anchor.getAttribute("rel") == "external") {
		anchor.target = "_blank"; 		 
		if (anchor.title) anchor.title += " (external site )";
		if (!anchor.title) anchor.title = "external site ";
	} 
} 
} 
window.onload = linkesterno;